Field of the Invention
The invention falls within the field of methods for producing components from composite materials.
Discussion of Related Art
The use of composite materials allows for the production of components with high strength and high rigidity compared with other lightweight materials. At the same time, fiber-reinforced composite materials in particular have a unique, characteristic appearance which is felt to be aesthetically pleasing and deemed a necessary feature for high-quality composite components.
DE102008035918A1 held by Bayer MaterialScience and Webasto AG was published in 2008 and discloses a method for producing a composite component. In this method, a decorative composite and stability-enhancing structural composite are produced at separate locations and then assembled by means of an interconnecting layer. The separate construction and curing of the two composite parts supposedly means the production time can be cut. The decorative composite consists of at least one support layer and at least one coloring layer. The structural composite consists of at least one top layer and a spacer. The decorative composite is not part of the supporting structure but rather serves decorative functions.
US7846366B2 held by GM Global Tech Operations Inc. was published in 2008 and describes compression molding cosmetic panels from fiber-reinforced composite materials. For this purpose, in a first step fiber mats are placed together with a curing resin into a first molding tool and, when the tool is closed, preformed and cured in part under the influence of pressure and heat. Then the component is brought into the final shape and cured in full in a second mold under higher pressure and higher temperatures. For shaping the component surface, the second molding tool has a higher quality surface finish than the first molding tool. The fibers are visible from the exterior.
U.S. Pat. No. 4,587,160 held by Ferro Corporation was published in 1986 and deals with the production of surfaced-coated plastics parts. An electrically conductive paint is applied to the surface of a hot mold by electrostatic adhesion. Then plastics material is introduced into the mold, the mold is closed and the surface layer shaped together with the plastics material.
EP0365414B1 held by Hutchinson was published in 1990 and discloses a method for producing a body part for motor vehicles. In this method, first of all a liquid paint is applied to the walls of a casting mold. In particular, provision is made for use of an electrically conductive paint which automatically detaches itself from the surface layer, so that later there is still the option of carrying out electrostatic powder coatings. Then a reinforcing element, such as a glass-fiber mat is deposited in the mold and a polymerizing material is injected therein, said material acting as a matrix for the reinforcing element and simultaneously interconnecting to the paint layer. In this manner, the production of components with a high-quality surface finish is supposedly possible.
EP1043138B1 (or US6235228B1) held by Morton International Inc. was published in 2000 and discloses a method for coating a molded object. For this purpose, a thermosetting powder mixture of an unsaturated polyester resin, a cross-linking prepolymer and a thermal initiator is applied to the surface of a molding tool. Then the surface of the molding tool coated with the powder is heated, which prompts the powder to transform into a continuous film that coats the molding tool surface and ultimately results in curing of said film. Alternatively, the molding tool is also heated prior to application of the powder mixture, so that the powder mixture liquefies upon contact with the surface. Then, in the molding tool, the actual component body is constructed on the cured powder coating. A filler resin, optionally interspersed with glass fibers, or layers of glass-fiber mats can be used. Once the component body has been cured, it is integrally interconnected to the powder coating and removed from the molding tool.
WO10008599A1 held by New England Catalytic Technologies Inc. was published in 2010 and discloses a method for the in-mold application of a powder coating. This method is intended to allow for a uniform, in-mold powder coating of a large component, without the molding tool used having to be heated beyond the melting point of the coating powder prior to introduction thereof. The surface of the cavity used is electrically conductive and earthed. The surface coating is produced by the surface coating powder being applied to the cavity wall at the same time as an electrically conductive and mainly carbon-fiber-containing fibrous medium and as an, optionally fibrous, reinforcing medium, the electrically conductive medium being in electrical contact with the electrically conductive surface of the cavity. Once applied, the surface coating is then heated to achieve thermosetting and is pressurised.
WO08061661A1 held by Novation S.p.A. was published in 2008 and discloses a method for producing components from fiber-reinforced plastics materials. In this method, first of all a molded main body is produced in a closed mold by injecting a thermosetting matrix system into a first type of fiber and curing (resin transfer molding, hereinafter “RTM”). After removal from the mold, at least one layer of a pre-impregnated fiber product (the “prepreg”) is laminated as a mechanical reinforcement on the molded main body and cured, resulting in a solid interconnection between the main body and the prepreg. Through the use of an optionally thermoplastics film applied to the component surface in conjunction with the prepreg, a high-quality surface finish can be achieved in the region of the visible surface component, which finish is suitable for any autoclaved component based solely on the prepreg.
WO03080310A1 held by Menzolit Fibron GmbH was published in 2003 and discloses a method for producing a painted, fiber-reinforced component. For this purpose, a film is preformed in a molding tool and assigned the surface condition desired for the component and optionally a color. Then, in a molding tool, reinforcing plies of fiber-reinforced plastics material are placed onto the side of the film that is not intended to be the component surface. By means of curing a thermosetting matrix system or of melting and subsequently cooling a thermoplastics matrix, the component to be produced is then molded.
EP1885547B1 held by Mubea Carbo Tech GmbH was published in 2006 and discloses a method for producing a coated composite product. For this purpose, in an auxiliary molding tool, a film-like basic shape is produced which corresponds at least in part to the surface shape of the component to be produced. Then this basic shape is removed from the auxiliary molding tool and reinforcing plies applied thereto. The basic shape is then transferred together with the reinforcing plies into a production tool, where the reinforcing plies are bound by a matrix system and then cured. Thereupon the basic shape is removed from the mold together with the reinforcing plies and can be finished. The basic shape can be assigned various functions under this patent specification; for example, the basic shape might be a high-quality component surface, provide shatter resistance, protect the surface of the production tool from damage, be strippable or protect the surface of the component from dirt until the point of finishing.